If you've ever asked yourself Why does my hair hurt?, you're not alone. It's that bizarre sensation that something is amiss at your roots—not quite a headache and not alleviated by simply taking down your ponytail. It's your actual hair hurting (or, at least, your scalp). Well, you aren't just imagining it—scalp pain is real, and it's quite common. There are a few factors that can cause this phenomenon, but the top offender is not washing your hair. Earlier this year, Vogue highlighted this puzzling issue, reaching out to experts to weigh in on what's at work.

"It's not actually your hair that hurts, but the skin and perifollicular area of the scalp—the region around each hair, pore, or follicle," Francesca Fusco, a Manhattan-based dermatologist, explains. "The scalp is incredibly rich in blood supply, nerve endings, and oil glands. Additionally, this yeast (pityrosporum) builds up, leading to dandruff. The combination of these factors can cause inflammation, which translates to sensitivity that can feel like your hair hurting."

We often exacerbate the problem because of our tendency to tie up greasy hair in buns and ponytails. Failing to switch up your hairstyle (wearing braids or a high ponytail day after day) can also worsen the pain. Harry Josh, celebrity hairstylist and the man behind the eponymous haircare brand, compares the hair hurting problem to not working out for a week. "If you don't wash your hair and keep it in the same style, it feels sore because it's lacking hair and scalp stimulation." In other words, if you're going to skip the shampoo, be sure to brush your hair and change up your hairstyle.

A final explanation for scalp pain is a phenomenon known as allodynia, which affects two-thirds of migraine sufferers. "Individuals with migraines may experience the sensation that a mere wind blowing, a hat, or a light touch to the scalp elicits pain," explains Fusco. If you think this is the case, rather than under-washing or overstyling, consult your doctor, and see if a migraine medication might be right for you.